Beer dispensing instrumentalities and method

ABSTRACT

A method of dispensing beer out of a single faucet from one, or from a number of kegs separately connected by suitable ducts with a header communicating with the faucet. A control valve device for each keg has a chamber forming a part of its duct. Float valves, one in each chamber, are operable upon decrease in the amount of fluid in their chambers to interrupt communication between the chamber outlets and the header. Differential pressure actuated valve means in each chamber functions to interrupt communication between its interior and the chamber inlet in response to decrease in pressure at said inlet.

United States Patent [191 Nezworski lll] 3,878,970

[451 Apr. 22, 1975 BEER DISPENSING INSTRUMENTALITIES AND METHOD [21]Appl. No.: 441,140

[52] US. Cl. 222/61 [51] Int. Cl 867d l/04 [58] Field of Search 222/64,55, 56, 65, 66,

[56] References Cited UNITED STATES PATENTS Hixon et al. l37/2663.l94,434 7/l965 Evanson 137/256 X Primary Examiner-Stanley l-I.Tollberg 5 7 ABSTRACT A method of dispensing beer out of a single faucetfrom one, or from a number of kegs separately connected by suitableduets with a header communicating with the faucet. A control valvedevice for each keg has a chamber forming a part of its duct. Floatvalves, one in each chamber, are operable upon decrease in the amount offluid in their chambers to interrupt communication between the chamberoutlets and the header. Differential pressure actuated valve means ineach chamber functions to interrupt communication between its interiorand the chamber inlet in response to decrease in pressure at said inlet.

21 Claims, 6 Drawing Figures PATENTED APR22 I975 SHEET 3 if M50461 d0Pm03 u OP BEER DISPENSING INSTRUMENTALITIES AND METHOD BACKGROUND OF THEINVENTION This invention relates to apparatus for dispensing liquidsfrom pressurized containers thereof. and has more particular referenceto beer dispensing systems.

Multiple barrel beer dispensing systems are now in widespread usebecause of their convenience to the bartenders and other persons whodispense beer. With a number of barrels, or kegs, supplying a commonfaucet, tapping need not be performed as frequently as when but onebarrel at a time is connected to the faucet. In fact, it is oftenpossible with multiple barrel dispensing to leave the tapping chore tothe delivery man who usually calls on his customers in accordance with aprearranged schedule to substitute full kegs for emp-' ties.

However, all multiple barrel dispensing systems in use in the past havehad serious disadvantages.

In the most widely used multiple barrel dispensing system heretoforeemployed, the kegs were connected in series between the dispensingfaucet and the source of gas pressure. As a result, the beer flowingfrom each keg to the adjacent downstream keg had to be introduced intothe latter through the gas passage of its tapping device.

With tapping devices such that of the Taubenheim US. Pat. No. 3,596,810,satisfactory dispensing of beer from multiple barrel series typedispensing systems was possible because the gas and beer passages inthose tapping devices were arranged concentrically with respect to oneanother. This enabled the gas passage in those tapping devices to have across sectional area large enough to enable beer to flow through itwithout being unduly restricted.

The widely used Hoff-Stevens tapping devices of the Stevens, Jr. US.Pat. No. 3,228,413, however, have the gas and beer passages formed byside-by-side parallel bores, and as a result the gas passage is toosmall to satisfactorily accomodate the flow of beer. Consequently,connection in series of a number of beer kegs equipped with Hoff-Stevenstapping devices so seriously reduced beer dispensing rates as to rendersuch a system completely unacceptable, even with objectionably high gaspressure on the endmost keg of the series.

It is this objection to the Hoff-Stevens tapping de vices which led tothe development of a multiple keg beer dispensing system in which theseveral kegs are individually connected with the source of gas underpressure, and their beer passages are selectively and separatelyconnectable with a single faucet through an electrically operatedmultiport distributor valve mechanism having manual selector meansremote therefrom but readily accessible to the bartender at thedispensing station behind the bar. Thus, whenever one keg becomes empty,the bartender actuates the selector means to effect disconnection of theempty keg from the faucet and connection of a full keg with the faucet.

But that selector valve system has a serious objection in addition toits high cost. As in all single barrel dispensing systems, aconsiderable amount of beer in the supply line leading to the faucet islost each time a keg connected therewith empties. When that occurs, thesupply line fills with an excessively foamy and unsaleable product, andissue thereof from the faucet constitutes the only warning that theempty keg must be replaced by a full one; as through the selector valveof the new system.

The only way to purge the foam from the supply line was to draw freshbeer from the newly connected keg. Since supply lines feet or more inlength are not uncommon, considerable time was spent in such purging,along with the loss of a substantial amount of beer.

SUMMARY OF THE INVENTION With these objections and observations in mind,it is a purpose of this invention to provide an improved method ofdispensing beer from one or from a number of barrels thereof, thepractice of which method eliminates the objections to and disadvantagesof past dispensing systems as well as those presently in use.

More particularly, it is an object of the invention to provide a beerdispensing system which features a novel control valve device for eachbarrel ofa beer dispensing system, which for the first time makespossible the advantageous connection of a number of barrels in parallelwith the supply line leading to the dispensing faucet.

It is another purpose of the invention to provide novel control valvemeans by which one or a plurality of beer kegs can be connected with afaucet in a system far superior to any heretofore available.

With these observations and objectives in mind, the manner in which theinvention achieves its purpose will be appreciated from the followingdescription and the accompanying drawings, which exemplify theinvention, it being understood that changes may be made in the precisemethod of practicing the invention and the specific apparatus disclosedherein without departing from the essentials of the invention set forthin the appended claims.

The accompanying drawings illustrate several complete examples of theembodiments of the invention constructed according to the best modes sofar devised for the practical application of the principles thereof, andin which:

FIG. 1 somewhat diagrammatically illustrates a system which is typicalof the parallel type multi-keg beer dispensing method of this invention;

FIG. 2 is a sectional view through one of the control valve devices,taken on the line 2-2 of FIG. 1;

FIG. 3 is a diagrammatic view of the control valve devices which makepossible the parallel connection of a number of beer barrels with asingle faucet, indicating the valve devices as housed in a single body;

FlG. 4 is a fragmentary sectional view illustrating the way in which thecontrol valves can be gang connected, with their outlets providing acommon delivery header; and

FlGS. 5 and 6 are modified types of control valve devices in whichsolenoid type outlet valves are employed.

Referring now to the accompanying drawings, the numeral 10 generallydesignates a walk-in cooler containing a battery of beer kegs ll, 12 and13. Ducts 14, one for each keg, connect the tapping units 15 of theindividual kegs with a common supply line 16 leading to a faucet 117. Adispensing system comprising three kegs has been shown by way of exampleonly, as this invention makes possible connection of several more withthe supply line, if desired.

Carbon dioxide gas under pressure, from a cylinder not shown, issupplied to the gas passage in each tapping unit through its nipple 18and a tube 19 connecting the tapping unit with a common gas supply line20. A shut-off valve V is connected in each of the tubes 19.

According to this invention, the kegs or barrels are communicated withthe beer supply line 16 leading to the faucet 17 through control valvedevices 25, one for each barrel, having a chamber 26 inits interiorforming in effect a part of the duct 14 by which its barrel iscommunicated with the beer supply line. Since these control valvedevices are identical, a description of one will suffice for all.

The control valve device comprises a body 27 which, for example, can bemade of complementary upper and lower body sections 28 and 29,respectively, having telescoping parts held together by screws 30 andsealed against leakage by an O-ring 31. The body can, if desired, be ofrectangular or square cross section, and it is elongated vertically,with its chamber 26 in an upright position.

An inlet 33 opens laterally to the top of the chamber, and an outlet 34opens downwardly from its bottom into a crossbore 35 in the lowerportion of the body, which crossbore extends entirely therethrough fromone side of the body to the other.

As shown in FIG. 1 and indicated in phantom lines in FIG. 2, the severalvalve devices 25 are mounted in a holding bracket 36 which is adaptedfor attachment to one of the walls 37 of the walk-in cooler at alocation near the barrels, and in a way that leaves a space 38 behindthe bracket. The inlets 33 of the valve devices open rearwardly towardthe wall 37 to enable the ducts 14 from the barrels to be run up throughthe space 38 and have concealed connections (not shown) with the valveinlets 33.

It should be noted that the valve devices have been illustrated asseparate self-contained units, much as sectional hydraulic valves whichare stacked together in a bank. However, they can also comprise thedesired number of valve mechanisms contained in a housing common to allof them, as seen more or less diagrammatically in FIG. 3.

In the present case, the valve bodies are confined by the walls of theholding bracket 36 in snug side-by-side relationship, with theircrossbores in register with one another. Annular couplers 39 seen bestin FIG. 4, have their opposite axial ends received in counterbores 40 towhich the crossbores open. O-rings 41 encircling the end portions of thecouplers establish leakproof seals between the crossbores of each pairof adjacent valve bodies.

The bores 42 of the couplers provide uninterrupted communication betweenthe crossbores, so that they can be said to cooperate in the provisionof an outlet manifold or header 43 common to all the control valvedevices.

The supply line 16 is coupled to the header at the right hand end of thebank of valves by any suitable connecting means 44. The counterbore inthe other end of the header is closed by a removable plug 45, held inplace by the adjacent end wall 46 of the holding bracket 36 or in anyother suitable way.

From the description thus far, it will be seen that the kegs 11, 12 and13 are connected in parallel with the beer supply line 16, so that it ispossible for beer from any one of the kegs to enter the inlet 33 of itsassociated control valve device and flow down through the chamber 26therein to the outlet manifold 43 defined by the crossbores 35 in thevalve bodies and the connecting couplers 39.

Such flow through any one of the valve devices, however. can only takeplace at times when the faucet 17 is opened, and a hollow float member47 in the valve chamber 26 is in what can be termed a neutral orfloating position, between upper and lower limits of mo'Jon within saidchamber. Preferably the float member has ears 47' projecting from itssides to engage the side wall of the valve chamber and keep the floatmember centered therein.

The upper and lower limits of float motion are defined by the top andbottom annular valve seats, 48 and 49, respectively, in each chamber 26,through which beer entering the chamber must flow to reach its outlet34. An O-ring 50 encircling the upper portion of the float 47 isengageable with the upper seat 48 to close off communication between theinlet and outlet of its chamber. In like manner, a similar O-ring 51encircling the lower portion of the float is engageable with the bottomseat 49 to disrupt communication between the inlet and outlet of thechamber.

It will be noted that the valve seat 48 is defined by an upwardlyconvergent conical wall surface in the upper portion of the chamber 26;and that the lower valve seat 49 is similarly defined by a downwardlyconvergent substantially conical wall surface in the bottom portion ofthe chamber.

At the time the beer dispensing system of this invention is initiallyplaced in use, beer under pressure in the kegs will not flow through thechamber 26 of any of the control valve devices to the beer supply line16 for the reason that keg pressure at the inlets of the control valvedevices will hold the float valves 47 thereof downwardly in their outletclosing positions.

For this reason, at least one of the control valve devices must beprovided with a plunger mechanism 53 by which the float therein can bemanually lifted off of its lower seat 49. This plunger mechanismcomprises a plunger 54 which extends through a downwardly opening hole56 in the bottom of the valve body, coaxial with but smaller in diameterthan the outlet port 34. The outer end of the plunger is fixed to theend wall of a cup shaped cap 56 having its side wall telescopinglyengaged over the side wall of a smaller cup 57 whose end wall is inengagement with the underside of the valve body and has a centralaperture therein to receive the plunger. A spring 58 encircling theouter end portion of the plunger is confined between the end walls ofthe two cups 56 and 57 to thereby yieldingly urge the plunger downwardlyto an inoperative position defined by the engagement of a collar 59 onits inner end with the shoulder formed by the function between theoutlet port 34 and the smaller diameter hole through which the plungerpasses.

A reduced upper end portion 60 on the plunger projects into the outletport 34 toward the underside of the float member 47, but terminates aslight distance short of it when the float is in its downward limit ofmotion engaging seat 49.

It will thus be seen that upward manual actuation of the cap 56 willengage the upper end portion 60 of the plunger with the float member andlift it off of its seat 49. When this is done, beer from the inlet 33 inthat valve device whose float has been thus lifted will flow into thechamber 26 thereof and beneath the float member to the crossbore 35thereunder, and hence to the outlet manifold 43. The plunger mechanism53 can then be released, for the pressures in the upper and lower (inletand outlet) portions of all the valve chambers 26 will at that time beequalized to allow the float valves to assume floating positionsintermediate their upper and lower limits. This is to say that thebuoyancy of the float valve in each control valve device will then holdit in its neutral position.

All three kegs are thus simultaneously in parallel with the outletmanifold 43 and beer supply line 16. For well known reasons, however,beer will first flow from and empty the keg 13 which is closest to thefaucet. The keg 12 next in line will be the second to empty, and the keg11 will be the last.

It is one of the features of the dispensing system of this inventionthat the float valve in each of the control valve devices will remain inits neutral position as long as beer fills, or is at a high level in itschamber 26.

As soon as keg l3 empties, for example, the duct l4 connected therewithwill fill with a non-liquid gas and foam emulsion, and the liquid levelin the chamber 26 of its associated control valve device will descend.When it reaches a low level designated L in FIG. 3, its float valve willengage the lower seat 49 and close off the chamber from the outletmanifold and supply line 16. It is important to observe that this willoccur before all of the liquid beer has left the chamber 26.

This seated condition of the float valve can be observed, for example,by having at least the lower section 39 of each valve body made of clearplastic material, and by applying a suitable coloring (red or orange) tothe float member 47 therein. Merely by way of example, the hollow floatmember has been shown as having a cylindrical wall also of clearplastic, with an orange strip 61 of paper or the like confined in itslower interior portion to be readily visible therethrough.

When any float is in its lowermost position, its colored portion can beseen through a suitable cut-out forming a window 62 in the front wall ofthe holding bracket 36 in which the valve devices are mounted.

As soon as the keg 13 is emptied, therefore, the float in its associatedcontrol valve will close off the outlet of the chamber therein. as shownin FIGS. 3. This prevents gas in the keg from entering the supply line16 and creating the foamy condition in the beer in said line thatheretofore rendered the beer unusable. Beer from the second keg 12 willautomatically then be dispensed as required, without loss ordeterioration of the beer in the supply line 16.

Though not essential at this time, the tapping unit can then be removedfrom the keg l3 and installed in a fresh keg of beer.

During the time the empty keg 13 remains connected by its duct 14 withthe chamber of its associated control valve, gas pressure from themanifold will act upon the float valve 47 in said chamber to firmly holdit in its outlet closing position against the equal pressure of beer inthe crossbore 35 beneath the float valve. This is possible because thearea at the top of the float valve exposed to gas pressure issubstantially greater than the area at the underside of the float valveexposed to pressure of beer in the outlet manifold.

At the time the tapping unit is to be removed from the empty keg 13, thevalve V in the gas line leading to that keg is first closed. As aresult, the upper chamber portion of the associated control valve devicewill then no longer be communicated with the source of gas underpressure. Consequently, the float valve will be immediately drivenupwardly to its inlet closing position in response too the pressure ofbeer in the manifold 43. The upwardly seated float valve will thenprevent beer under pressure in the manifold from reaching the inlet 33of the control valve device associated with the empty keg 13.

Upon replacement of the empty keg 13 with a fresh one, there will be asmall amount of foam in the short duct 14 connecting it with the inletof its control valve device. According to this invention, such foampresent in the duct 14 after the new keg has been installed can bequickly eliminated by depression of a second plunger mechanism 65 on theassociated control valve device, there being one required on the top ofeach. The plunger mechanism 65 is generally like the mechanism 53described earlier, except that depression of its plunger 66 disengages avalve member 67 from a seat against which it is spring urged, to therebyestablish communication between the upper or inlet portion of chamber 26and a vent port 68. The inner end 69 of the plunger is reduced indiameter, and long enough that when depressed, it will force the floatvalve off of its upper seat 48 for a purpose to be later discussed.

The plunger mechanism 65 need only be held depressed for a second ortwo, which is ordinarily long enough to enable pressurized liquid fromthe new keg to expel the foam from its short duct 14 and from the upperportion of its valve chamber. As seen best in FIG. 1, the vent ports 68can, if desired, be connected with a common waste line 70.

It is believed to be obvious from the description thus far, that neitherkeg 12 nor 13, when emptied, need be at once replaced with a fresh keg.The contents of the third one ll of the three parallel connected kegswill. of course, be available for dispensing from the faucet when thekegs l2 and 13 become empty.

The valve devices described are constructed in a way that facilitatescleansing thereof and of the ducts 14 and 16 connecting therewith. Forsuch cleansing, the kegs are disconnected from the system, either bydetachment of the outer components of their tapping units 15 or bydetachment of the ducts 14 from said outer tapping components.

To clean the manifold and supply line 16, the plug 45 at the dead end ofthe manifold can be replaced by an adapter to enable cleansing liquidunder pressure to be directed into the manifold. When the faucet is thenopened, cleansing liquid will flow through the manifold and the duct 16,and discharge from the faucet.

If the faucet is then closed, depression of each of the plungermechanisms 65 in turn, will cause cleansing liquid in the manifold toflow up through the associated valve chamber 26 for discharge of part ofthe liquid through the vent port 68 and drain line 70, and the remainderof the liquid through the associated duct 14, providing the latter isdisconnected from its keg. This, of course, will enable the chambers 26,the drain line 70, and the ducts 14 to be cleaned.

Such cleansing of the mechanism and ducts can also be accomplished withthe manifold plug 45 in place, by introducing the cleansing liquid intothe system through the faucet l7. If the outer tapping components orcoupler" are of the type disclosed in the Taubenheim US. Pat. No.3,596,810 issued Aug. 3, 197 l they as well as the ducts l4 connectingtherewith can be cleansed in the manner described providing the checkvalves in the couplers are held open to allow cleansing fluid todischarge past them.

lnasmuch as thorough cleaning of the interior of each control valvedevice will entail passage of cleansing liquid through its chamber for amore or less extended period of time, the plunger mechanisms 65 arepreferably provided with latch mechanisms, generally designated 75, toenable them to be releasably held in depressed condition.

Each such latch mechanism 75 has been shown as comprising a screw 76threaded downwardly into the top of the valve body alongside the cap 77of the plunger mechanism. An upwardly facing ledge 78 on the cap 77 isengageable under the head 79 on the screw to hold the plunger mechanismin its depressed condition.

The head 79 of the screw is normally received in a depression 80 in theside of the cap, which depression constitutes a localized interruptionin the ledge 78. For this reason, the cap must be turned slightly afterit has been fully depressed, to bring an uninterrupted portion of itsledge under the screw head. To release the plunger mechanism from thelatch, it is only necessary to turn the cap 77 to the position at whichits depression 80 registers with the head 79 of the screw. The springacting upon the plunger mechanism will then return it to its outwardposition at which it closes off the chamber 26 from the vent port 68.

In cases where the components of two or more complete systems such asillustrated in FIG. 3 require cleaning, their valve devices and outletmanifolds can be cleansed simultaneouly by connecting the latter eitherin series or in parallel with the source of cleaning liquid underpressure.

It should here be emphasized that because the beer kegs are connected inparallel with the beer supply line 16 and with the gas pressure source,the dispensing system of this invention can comprise more than the threekegs shown in the drawings by way of example, as long as each keg hasits own control valve device 25.

Moreover, the system of this invention is ideally suited for dispensingbeer from single keg installations. This follows from the fact that thefloat valve in the control valve device for the single keg will descendto its downwardly seated position as soon as the level of beer in itschamber 26 drops to the level where it will no longer float the valve.As mentioned earlier, this must occur before all of the beer has leftthe chamber, to prevent the beer in the supply line from becoming foamyand unusable, as it does in conventional dispensing systems, withattendant loss of profit, at the time the keg connected therewithbecomes empty.

The modified embodiments seen in FIGS. and 6 also provide for dispensingof liquids under pressure. such as beer, in accordance with the methodof this invention. Briefly stated, this method is characterized byflowing beer (or other liquid under pressure) downwardly through achamber to a faucet connected beer supply line, and interruptingcommunication between the inlet and outlet of the chamber at such timesas the liquid therein falls to a predetermined low level.

In FIG. 5, a control valve device 90 which'will perform this importantstep of the method in a single barrel installation, is characterized bya normally closed electromagnetic valve 91 in the outlet 92 from itschamber 93. The chamber has an inlet port 94 in an upper portionthereof, to enable downward flow of beer therethrough, providing theelectromagnetic valve 91 is open.

The solenoid 95 of the valve 91 is energizable from a current source 96whenever a pair of electrodes 97, 98 is electrically bridged by beer inthe chamber 93. These electrodes are located opposite one another, aboutone-half way between the inlet 93 and outlet 92. When bridged in thismanner, an energizing circuit is completed for the solenoid 95 to effectopening of valve 91. This enables beer to flow through a supply lineconnected with the outlet 92, to a faucet for dispensing as desired.

The valve 91 will remain open as long as the chamber is filled withbeer. When the beer barrel empties, the level of beer in the chamber 93will fall until the electrodes 97, 98 are no longer electrically bridgedthereby. When that occurs, the energizing circuit for the solenoid 95 isbroken, and the valve'9l returns to its normally closed position whilethere is still a small amount of beer in the chamber. This is animportant feature of the invention, as it prevents foam formation in thesupply line leading to the faucet from the outlet 92 of the controlvalve device, and thus assures against loss of the beer therein.

A plunger mechanism is also mounted on the top of the valve body, toprovide for venting the upper portion of the chamber 93 for the reasonsdiscussed hereinbefore.

It will be seen therefore, that the valve device is like thosepreviously described in that its outlet is controlled by valve means atthe dictate of detector means (electrodes) under the control of theliquid level in the chamber 93. The float in the first describedembodiment of the invention similarly constitutes detector means havingthe same purpose.

The control valve device 190 of FIG. 6 also features an electromagneticvalve 100 to control flow of beer through the outlet 101 of the chamber102 in the interior of the device. Again in this case, a beer inlet port103 opens to the top of the chamber to enable beer to flow downwardlytherethrough for discharge through its outlet 101 providing theelectromagnetic valve 100 is open.

The valve 100 is of the normally open type, and it is adapted to closeupon establishment of an energizing circuit for its solenoid 104. Thesolenoid is in an energizing circuit controlled by a reed switch 106,which extends coaxially down into the chamber 102 from its top. Thecontacts of the reed switch are normally open, and are closed by thefield of a permanent magnet 107 here shown as mounted in the bottomportion of a float 108 which encircles the envelope of the reed switch.

Beer in the chamber 102 normally raises the float 108 to a level such asshown, at which its magnet has no influence upon the contacts of thereed switch. The switch thus remains open as long as beer in the chamberis at a level well above the outlet 10].

The level of beer in the chamber will descend, as the beer keg connectedtherewith becomes empty. At that time, the float 108 will likewisedescend, until its magnet 107 comes opposite the contact ends of thearms in the reed switch. When that occurs, the switch closes to energizethe solenoid 104 and effect closure of the valve 100. Such closure ofthe valve 100 will again occur before the level of beer in the chamber102 drops far enough to cause foaming of the beer in the outlet l] andthe supply line connecting the same with a faucet.

Here again, the magnetically controlled reed switch constitutes detectormeans on the order of the float type of level detector in the firstdescribed embodiment of the invention; and a plunger mechanism 65' isalso provided to effect venting of the space in the upper portion of thechamber 102, whenever necessary.

From the foregoing description. together with the accompanying drawings.it will be readily apparent to those skilled in the art that thisinvention provides a vastly improved dispensing system for beer andother liquids under pressure.

The invention is defined by the following claims:

1. A control instrumentality to govern communication of a dispensingdevice with a container holding liquid under pressure, characterized by:

A. means defining a chamber through which liquid from the container mustflow to reach a dispensing device, said chamber having inlet and outletmeans in upstream and downstream portions thereof, respectively, toprovide for such flow;

B. first valve means adjacent to the chamber outlet means to govern flowof liquid out of the chamber;

C. means to govern actuation of said valve means between open and closedpositions, comprising detector means sensitive to the presence andamount of liquid in the chamber for effecting opening of said valvemeans in consequence ofliquid in the chamber above a predeterminedlevel. and to effect closure of said valve means in consequence ofdecrease in the amount of liquid in the chamber to a lower level thatleaves it only partially filled with liquid;

D. second valve means to control communication between the chamber andthe inlet means;

E. and means to effect closure of said second valve means in consequenceof drop in pressure at the inlet means to a valve below that prevailingat the outlet means.

2. The control instrumentality of claim 1, further characterized by:

A. said inlet and outlet means comprising opposing valve seats in topand bottom portions. respectively. of the chamber;

B. said detector means comprising a float member in said chamber;

C. and said first and second valve means comprising valve memberscarried by the float member, at top and bottom portions thereof, forcooperation with said valve seats.

3. The control instrumentality of claim 2, further characterized by:

A. said chamber having walls defining a valve body;

B. and means on the body by which said float member can be manuallylifted to effect opening of the outlet means.

4. The control instrumentality of claim 2, further characterized bymanually operable means for venting the upper portion of the chamber.

5. A control instrumentality to govern communication ofa dispensingdevice with a plurality of containers holding liquid under pressure,characterized by:

A. means defining a plurality of chambers. one for each container.through which liquid from its container must flow to reach a dispensingdevice, each chamber having inlet and outlet ports in upstream anddownstream portions thereof, respectively, to provide for such flow;

B. means providing a common header connecting said outlet ports,through; which liquid can flow to a dispensing device;

C. first valve means adjacent to the outlet port of each chamber,between said chamber and the header;

D. means to govern actuation of said first valve means between open andclosed positions, comprising detector means sensitive to the presenceand amount of liquid in the chamber, for effecting opening of said firstvalve means in consequence of filling of the chamber with liquid, and toeffect closure of said first valve means in consequence of apredetermined decrease in the amount of liquid in said chamber;

E. and second valve means for each chamber, adjacent to its inlet port,to effect closure thereof in consequence of drop in pressure at saidinlet port to a value below that prevailing in the header.

6. The control instrumentality of claim 5, further characterized by:

A. said inlet and outlet ports of each chamber comprising opposed upperand lower valve seats, respectively;

B. said detector means comprising a float member in each chamber;

C. and said first and second valve means comprising valve memberscarried by each float member. at top and bottom portions thereof. forcooperation with the valve seats.

7. The control instrumentality of claim 6. further characterized by:

A. manually operable means for effecting venting of the upper portionsof each of each chambers;

B. and manually operable means for lifting the float member in one ofsaid chambers from a position. closing its outlet port to a position atwhich its outlet port is open.

8. In combination with the control instrumentality of claim 1:

A. said container comprising a beer keg under carbon dioxide gaspressure;

B. a first duct connecting the outlet of said keg with the inlet meansof said chamber;

C. a faucet from which beer can be dispensed;

D. a second duct connecting the faucet with the outlet means of thechamber;

E. and said first valve means, when closed, serving to prevent gas fromentering said second duct.

9. In combination with the control instrumentality of claim 5:

A. a plurality of beer containers under carbon dioxide gas pressure;

B. a faucet common to said containers, from which beer therein can bedispensed;

C. a plurality of supply ducts, one for each container to connect theoutlet thereof with the inlet port of its associated chamber;

D. a supply line connecting said header with the faucet;

E. and said second valve means of one of said chambers being actuatableto its inlet closing position under the influence of fluid pressure inthe header at times when the container associated with said one chamberis being replaced by a full container.

10. The combination of claim 9, further characterized by means providinga signal to indicate when said outlet ports are closed by said firstvalve means.

11. The combinations of claim 10, further characterized by:

A. said first valve means for each chamber being located therein andhaving indicia thereon;

B. and each chamber having a transparent wall portion located to enablethe indicia on said first valve means therein to be viewed when thelatter is in its closed position.

12. A control instrumentality to govern communication ofa dispensingdevice with a container holding liquid under pressure, characterized by:

A. a body having a chamber with an inlet for connection with a containerof liquid under pressure, and an outlet for connection with a dispensingdevice;

B. valve means adjacent to the outlet of said chamber for governing flowof liquid through the outlet;

C. means governing opening and closing of said valve means. comprisingdetector means influenced by the presence and the amount of liquid inthe chamher, and adapted to effect opening of said valve means inconsequence of liquid filling the chamber to a high level and to effectclosure of the valve means in consequence of decrease in the volume ofliquid in the chamber by an amount which leaves it only partially filledwith liquid at a lower level;

D. and manually operable means for effecting venting of the chamber at alocation adjacent to its inlet.

13. The control instrumentality of claim 12, further characterized by:

A. said valve means comprising an electromagnetic valve which is closedexcept upon completion of an energizing circuit therefore;

B. and said detector means comprising a pair of electrodes which projectinto said chamber to provide for the establishment of an energizingcircuit for said electromagnetic valve when liquid in the chambercompletes an electrically conductive path between the electrodes.

14. The control instrumentality of claim 12, further characterized by:

A. said valve means comprising an electromagnetic valve which is openexcept upon completion of an energizing circuit therefor;

B. and said detector means comprising a reed switch instrumentalityhaving its contact end in said chamber, a float in the chamber. and apermanent magnet carried by said float to effect closure of the reedswitch and establishment of an energizing circuit for theelectromagnetic valve upon descent of the float to a predetermined lowlevel in the chamber.

15. The control instrumentality of claim 12, further characterized by:

A. said valve means comprising an electromagnetic valve;

B. and an energizing circuit for said electromagnetic valve, controlledby said detector means.

16. The combination with a container of pressurized liquid, a faucet,and duct means communicating the faucet with the container, of controlinstrumentalities operable to interrupt communication of said containerwith the faucet when the volume of liquid in the container is reduced toa predetermined minimum, said control instrumentalities comprising:

A. a valve body having a chamber forming a part of said duct means, andhaving inlet and outlet means opening to the chamber and respectivelycommunicating with said container and with the dispensing means;

B. a valve seat in the chamber, between said inlet and outlet means;

C. valve means movable to and from engagement with said valve seat tothereby close off communication between the container and the dispensingmeans; 7

D. the chamber being filled with liquid when that length of the ductmeans connecting the chamber with the container is filled, and thevolume of liquid in the chamber diminishing when said length of the ductmeans is no longer filled with liquid;

E. means responsive to a predetermined decrease in the volume of liquidin said chamber to effect seating of said valve means;

F. and means on the body providing for manually disengaging said valvemeans from its seat.

17. The combination of claim 16, further characterized by:

A. other valve means in the chamber movable toward and from a positionclosing the inlet means thereof;

B. said other valve means being pressure responsive and being actuatableto closed position whenever pressure at the inlet means drops to a valuebelow the pressure at the outlet means.

18. In combination with a container of liquid under pressure anddispensing means for said liquid including duct means connectng the samewith the container:

A. means providing a chamber which is connected in said duct means toform a part thereof;

B. valve means in said duct means adjacent to the downstream-side ofsaid chamber, movable to and from a position closing said duct means;

C. means governing opening and closing motion of said valve means,comprising detector means located in said chamber to be influenced bythe amount of liquid therein, and adapted to effect opening of saidvalve means in consequence of liquid filling said chamber and to effectclosure of said valve means in consequence of a predetermined decreasein he amount of liquid in said chamber;

D. and manually operable means for effecting venting of the upstreamside of said chamber.

19. A method of controlling communication ofa plurality of containersholding liquid under pressure with a common header from which the liquidcan be dispensed, which method is characterized by:

A. for each container, providing a chamber which has an inlet port in anupper portion thereof, an outlet port in a lower portion thereof, abuoyant valve device to close the outlet port when the liquid level inthe chamber drops to a predetermined low, and to close the inlet portwhenever outlet port pressure exceeds inlet port pressure;

B. ducting the inlet port of each chamber with the outlet of itscontainer whereby liquid therefrom will be able to flow to the outletport of its chamber as long as equal liquid pressures prevail at theinlet and outlet ports thereof;

C. and communicating the chamber outlet ports with the header, and withone another, whereby pressurized liquid in the leader will be capable ofholding the valve device in one of said chambers in an inlet closingposition at times when its associated container is being replaced by afull container and pressure is relieved at the inlet port of said onechamber.

20. A method of dispensing liquid through a common dispensing means froma plurality of pressurized containers for said liquid, which methodcomprises:

A. for each container. providing a control valve having a hollow body.an inlet port; an outlet port, and a movable valve member engageablewith a seat to close off communication between the said ports;

B. ducting each container with the inlet port of its respective controlvalve so that the interior thereof is full of liquid as long as theducting for said container is filled with liquid;

C. commonly connecting the outlet ports of said control valves with asupply line that leads to the dispensing means, so that as long as themovable valve member of one of said control valves is off its seat,pressurized liquid is available at the dispensing means;

D. and in response to reduction in the volume of liquid in the interiorof each control valve, effecting seating of its respective valve member,so that with the emptying of the last to empty container, the dispensingmeans is no longer communicated with any of the containers but thesupply line leading from the control valves to the dispensing meansremains filled with liquid.

21. A method of controlling communication of a plurality of containersholding liquid under pressure with a supply line from which the liquidcan be dispensed, which method is characterized by:

A. constraining liquid from each container to flow through a separatechamber having its outlet connected with the supply line;

B. closing the outlet of each chamber at times when the level of liquidtherein reaches a predetermined low level above the chamber outlet;

C. and closing the inlet of any one chamber at times when pressure atsaid inlet falls to a value below the pressure of liquid at the outletof any other chamber.

1. A control instrumentality to govern communication of a dispensingdevice with a container holding liquid under pressure, characterized by:A. means defining a chamber through which liquid from the container mustflow to reach a dispensing device, said chamber having inlet and outletmeans in upstream and downstream portions thereof, respectively, toprovide for such flow; B. first valve means adjacent to the chamberoutlet means to govern flow of liquid out of the chamber; C. means togovern actuation of said valve means between open and closed positions,comprising detector means sensitive to the presence and amount of liquidin the chamber for effecting opening of said valve means in consequenceof liquid in the chamber above a predetermined level, and to effectclosure of said valve means in consequence of decrease in the amount ofliquid in the chamber to a lower level that leaves it only partiallyfilled with liquid; D. second valve means to control communicationbetween the chamber and the inlet means; E. and means to effect closureof said second valve means in consequence of drop in pressure at theinlet means to a valve below that prevailing at the outlet means.
 1. Acontrol instrumentality to govern communication of a dispensing devicewith a container holding liquid under pressure, characterized by: A.means defining a chamber through which liquid from the container mustflow to reach a dispensing device, said chamber having inlet and outletmeans in upstream and downstream portions thereof, respectively, toprovide for such flow; B. first valve means adjacent to the chamberoutlet means to govern flow of liquid out of the chamber; C. means togovern actuation of said valve means between open and closed positions,comprising detector means sensitive to the presence and amount of liquidin the chamber for effecting opening of said valve means in consequenceof liquid in the chamber above a predetermined level, and to effectclosure of said valve means in consequence of decrease in the amount ofliquid in the chamber to a lower level that leaves it only partiallyfilled with liquid; D. second valve means to control communicationbetween the chamber and the inlet means; E. and means to effect closureof said second valve means in consequence of drop in pressure at theinlet means to a valve below that prevailing at the outlet means.
 2. Thecontrol instrumentality of claim 1, further characterized by: A. saidinlet and outlet means comprising opposing valve seats in top and bottomportions, respectively, of the chamber; B. said detector meanscomprising a float member in said chamber; C. and said first and secondvalve means comprising valve members carried by the float member, at topand bottom portions thereof, for cooperation with said valve seats. 3.The control instrumentality of claim 2, further characterized by: A.said chamber having walls defining a valve body; B. and means on thebody by which said float member can be manually lifted to effect openingof the outlet means.
 4. The control instrumentality of claim 2, furthercharacterized by manually operable means for venting the upper portionof the chamber.
 5. A control instrumentality to govern communication ofa dispensing device with a plurality of containers holding liquid underpressure, characterized by: A. means defining a plurality of chambers,one for each container, through which liquid from its container mustflow to reach a dispensing device, each chamber having inlet and outletports in upstream and downstream portions thereof, respectively, toprovide for such flow; B. means providing a common header connectingsaid outlet ports, through which liquid can flow to a dispensing device;C. first valve means adjacent to the outlet port of each chamber,between said chamber and the header; D. means to govern actuation ofsaid first valve means between open and closed positions, comprisingdetector means sensitive to the presence and amount of liquid in thechamber, for effecting opening of said first valve means in consequenceof filling of the chamber with liquid, and to effect closure of saidfirst valve means in consequence of a predetermined decrease in theamount of liquid in said chamber; E. and second valve means for eachchamber, adjacent to its inlet port, to effect closure thereof inconsequence of drop in pressure at said inlet port to a value below thatprevailing in the header.
 6. The control instrumentality of claim 5,further characterized by: A. said inlet and outlet ports of each chambercomprising opposed upper and lower valve seats, respectively; B. saiddetector means comprising a float member in each chamber; C. and saidfirst and second valve means comprising valve members carried by eachfloat member, at top and bottom portions thereof, for cooperation withthe valve seats.
 7. The control instrumentality of claim 6, furthercharacterized by: A. manually operable means for effecting venting ofthe upper portions of each of each chambers; B. and manually operablemeans for lifting the float member in one of said chambers from aposition closing its outlet port to a position at which its outlet portis open.
 8. In combination with the control instrumentality of claim 1:A. said container comprising a beer keg under carbon dioxide gaspressure; B. a first duct connecting the outlet of said keg with theinlet means of said chamber; C. a faucet from which beer can bedispensed; D. a second duct connecting the faucet with the outlet meansof the chamber; E. and said first valve means, when closed, serving toprevent gas from entering said second duct.
 9. In combination with thecontrol instrumentality of claim 5: A. a plurality of beer containersunder carbon dioxide gas pressure; B. a faucet common to saidcontainers, from which beer therein can be dispensed; C. a plurality ofsupply ducts, one for each container to connect the outlet thereof withthe inlet port of its associated chamber; D. a supply line connectingsaid header with the faucet; E. and said second valve means of one ofsaid chambers being actuatable to its inlet closing position under theinfluence of fluid pressure in the header at times when the containerassociated with said one chamber is being replaced by a full container.10. The combination of claim 9, further characterized by means providinga signal to indicate when said outlet ports are closed by said firstvalve means.
 11. The combinations of claim 10, further characterized by:A. said first valve means for each chamber being located therein andhaving indicia thereon; B. and each chamber having a transparent wallportion located to enable the indicia on said first valve means thereinto be viewed when the latter is in its closed position.
 12. A controlinstrumentality to govern communication of a dispensing device with acontainer holding liquid under pressure, characterized by: A. a bodyhaving a chamber with an inlet for connection with a container of liquidunder pressure, and an outlet for connection with a dispensing device;B. valve means adjacent to the outlet of said chamber for governing flowof liquid through the outlet; C. means governing opening and closing ofsaid valve means, comprising detector means influenced by the presenceand the amount of liquid in the chamber, and adapted to effect openingof said valve means in consequence of liquid filling the chamber to ahigh level and to effect closure of the valve means in consequence ofdecrease in the volume of liquid in the chamber by an amount whichleaves it only partially filled with liquid at a lower level; D. andmanually operable means for effecting venting of the chamber at alocation adjacent to its inlet.
 13. The control instrumentality of claim12, further characterized by: A. said valve means comprising anelectromagnetic valve which is closed except upon completion of anenergizing circuit therefore; B. and said detector means comprising apair of electrodes which project into said chamber to provide for theestablishment of an energizing circuit for said electromagnetic valvewhen liquid in the chamber completes an electrically conductive pathbetween the electrodes.
 14. The control instrumentality of claim 12,further characterized by: A. said valve means comprising anelectromagnetic valve which is open except upon completion of anenergizing circuit therefor; B. and said detector means comprising areed switch instrumentality having its contact end in said chamber, afloat in the chamber, and a permanent magnet carried by said float toeffect closure of the reed switch and establishment of an energizingcircuit for the electromagnetic valve upon descent of the float to apredetermined low level in the chamber.
 15. The control instrumentalityof claim 12, further characterized by: A. said valve means comprising anelectromagnetic valve; B. and an energizing circuit for saidelectromagnetic valve, controlled by said detector means.
 16. Thecombination with a container of pressurized liquid, a faucet, and ductmeans communicating the faucet with the container, of controlinstrumentalities operable to interrupt communication of said containerwith the faucet when the volume of liquid in the container is reduced toa predetermined minimum, said control instrumentalities comprising: A. avalve body having a chamber forming a part of said duct means, andhaving inlet and outlet means opening to the chamber and respectivelycommunicating with said container and with the dispensing means; B. avalve seat in the chamber, between said inlet and outlet means; C. valvemeans movable to and from engagement with said valve seat to therebyclose off communication between the container and the dispensing means;D. the chamber being filled with liquid when that length of the ductmeans connecting the chamber with the container is filled, and thevolume of liquid in the chamber diminishing when said length of the ductmeans is no longer filled with liquid; E. means responsive to apredetermined decrease in the volume of liquid in said chamber to effectseating of said valve means; F. and means on the body providing formanually disengaging said valve means from its seat.
 17. The combinationof claim 16, further characterized by: A. other valve means in thechamber movable toward and from a position closing the inlet meansthereof; B. said other valve means being pressure responsive and beingactuatable to closed position whenever pressure at the inlet means dropsto a value below the pressure at the outlet means.
 18. In combinationwith a container of liquid under pressure and dispensing means for saidliquid including duct means connectng the same with the container: A.means providing a chamber which is connected in said duct means to forma part thereof; B. valve means in said duct means adjacent to thedownstream side of said chamber, movable to and from a position closingsaid duct means; C. means governing opening and closing motion of saidvalve means, comprising detector means located in said chamber to beinfluenced by the amount of liquid therein, and adapted to effectopening of said valve means in consequence of liquid filling saidchamber and to effect closure of said valve means in consequence of apredetermined decrease in he amount of liquid in said chamber; D. andmanually operable means for effecting venting of the upstream side ofsaid chamber.
 19. A method of controlling communication of a pluralityof containers holding liquid under pressure with a common header fromwhich the liquid can be dispensed, which method is characterized by: A.for each container, providing a chamber which has an inlet port in anupper portion thereof, an outlet port in a lower portion thereof, abuoyant valve device to close the outlet port when the liquid level inthe chamber drops to a predetermined low, and to close the inlet portwhenever outlet port pressure exceeds inlet port pressure; B. ductingthe inlet port of each chamber with the outlet of its container wherebyliquid therefrom will be able to flow to the outlet port of its chamberas long as equal liquid pressures prevail at the inlet and outlet portsthereof; C. and communicating the chamber outlet ports with the header,and with one another, whereby pressurized liquid in the leader will becapable of holding the valve device in one of said chambers in an inletclosing position at times when its associated container is beingreplaced by a full container and pressure is relieved at the inlet portof said one chamber.
 20. A method of dispensing liquid through a commondispensing means from a plurality of pressurized containers for saidliquid, which method comprises: A. for each container, providing acontrol valve having a hollow body, an inlet port, an outlet port, and amovable valve member engageable with a seat to close off communicationbetween the said ports; B. ducting each container with the inlet port ofits respective control valve so that the interior thereof is full ofliquid as long as the ducting for said container is filled with liquid;C. commonly connecting the outlet ports of said control valves with asupply line that leads to the dispensing means, so that as long as themovable valve member of one of said control valves is off its seat,pressurized liquid is available at the dispensing means; D. and inresponse to reduction in the volume of liquid in the interior of eachcontrol valve, effecting seating of its respective valve member, so thatwith the emptying of the last to empty container, the dispensing meansis no longer communicated with any of the containers but the supply lineleading from the control valves to the dispensing means remains filledwith liquid.